[TASK] Avoid withConsecutive() in FileBackendTest

Resolves: #100480
Related: #100249
Releases: main
Change-Id: I256b6f6a8eae577033207df980c1b607d4226dae
Reviewed-on: https://review.typo3.org/c/Packages/TYPO3.CMS/+/78487


Tested-by: Christian Kuhn <lolli@schwarzbu.ch>
Tested-by: Oliver Klee <typo3-coding@oliverklee.de>
Tested-by: core-ci <typo3@b13.com>
Reviewed-by: Oliver Klee <typo3-coding@oliverklee.de>
Reviewed-by: Christian Kuhn <lolli@schwarzbu.ch>